Reciprocal variations in insulin-stimulated glucose uptake and pancreatic insulin secretion in women with normal glucose tolerance.

Objective: Maintenance of normal glucose tolerance is achieved in subjects with a wide range of insulin sensitivity. It follows, therefore, that the body must possess a sensor mechanism that assesses the body's sensitivity to insulin and appropriately adjusts the secretion of insulin to maintain normal glucose homeostasis. We evaluated the relation between insulin action and insulin secretion.

Fetal Doppler and behavioral responses during hypoglycemia induced with the insulin clamp technique in pregnant diabetic women.

Objective: This study was undertaken to assess human fetal behavior and fetal blood flow after insulin-induced symptomatic maternal hypoglycemia of sufficient magnitude to elicit counterregulatory hormones and a symptomatic response.

Study Design: Plasma glucose was lowered from approximately 95 mg/dl to 45 mg/dl in decrements of 10 mg/dl every 40 minutes with the insulin clamp technique. In 10 insulin-dependent diabetic women in the third trimester, the fetus was studied by monitoring fetal heart rate and recording fetal body and breathing movements and by performing Doppler waveform analysis with real-time ultrasonography.

Counter-regulatory response to hypoglycemia in the follicular and luteal phases of the menstrual cycle.

Objective: To assess whether the phase of the menstrual cycle influences the counter-regulatory response to hypoglycemia.

Design: Prospective randomized euglycemia-hypoglycemia clamp studies in the follicular and luteal phases of the menstrual cycle in the same woman.

Settings: Clinical Research Center, Yale University School of Medicine.

Glucose metabolism during the menstrual cycle. Assessment with the euglycemic, hyperinsulinemic clamp.

To assess tissue sensitivity to insulin during the follicular and luteal phases of the menstrual cycle, two-step euglycemic, hyperinsulinemic clamp studies in combination with tritiated glucose infusion and indirect calorimetry were performed in regularly menstruating women in randomized order. There was no difference in the basal follicular and luteal phase levels of glucose, insulin or glucose turnover. A low-dose (0.